Toxic alcohols are important components of many household, automotive, and industrial products, and they are frequently implicated in suicidal, unintentional, and even epidemic poisoning. Consideration of toxic alcohols as a cause of illness is also often encountered clinically in the differential diagnosis of a metabolic acidosis with an elevated anion gap. Evaluation of these patients is complex, in part because serum concentrations are not readily available in many institutions. Treatment involves a choice between the antidotes fomepizole and ethanol in addition to multiple other therapeutic modalities including hemodialysis, bicarbonate, thiamine, pyridoxine, and folate. Further complicating matters, the role of hemodialysis remains controversial despite a long history of its effective use in treating patients poisoned by toxic alcohols.
Methanol was a component of the embalming fluid used in ancient Egypt. Robert Boyle first isolated the molecule in 1661 by distilling boxwood, calling it spirit of box.23 The molecular composition was determined in 1834 by Dumas and Peligot, who coined the term methylene from the Greek roots for "wood wine."145 Industrial production began in 1923, and today most methanol is used for the synthesis of other chemicals. Methanol-containing consumer products that are commonly encountered include model airplane fuel, windshield washer fluid, solid cooking fuel for camping and chafing dishes, photocopying fluid, perfumes, and gas line antifreeze ("dry gas"). Methanol is also used as a solvent by itself or as an adulterant in "denatured" alcohol.95 Most reported cases of methanol poisoning in the United States involve ingestions of one of these products, with over 60% involving windshield washer fluid.38 In a Tunisian series, ingested cologne was the most common etiology.24 There have also been sporadic epidemics of mass methanol poisoning, most commonly involving tainted fermented beverages.18,90 These epidemics are a continuing problem in many parts of the world.12,105,133,173
Ethylene glycol was first synthesized in 1859 by Charles-Adolphe Wurtz and first widely produced as an engine coolant during the second World War, when its precursor ethylene oxide became readily available.47 Today its primary use remains as an engine coolant antifreeze used in car radiators. Antifreeze used in gas tanks generally contains methanol. Because of its sweet taste, it is unintentionally consumed by animals and children. Aversive bittering agents have been added to ethylene glycol-containing antifreeze to try to prevent ingestions by making the antifreeze unpalatable, an approach required by law in two states. However, no evidence suggest that this strategy is effective, and comparisons in poison center data between ethylene glycol ingestions where bittering agents were required and where they were not have revealed no significant differences in frequency or volume of ingestion, or any other outcome variable.170
Isopropanol is primarily available as rubbing alcohol. Typical household preparations contain 70% isopropanol. It is also a solvent used in many household, cosmetic, and topical pharmaceutical products. Perhaps because it is so ubiquitous, inexpensive, and ...